It's Getting Hot in Here: Energy-Saving Air Conditioner Tips

I lived in Tucson with an evaporative cooler that never got the apartment below 100F. Iced drinks and popsicles helped the most. Cleaning house in a damp bathing suit with damp hair made chores easier, especially washing dishes. Also, even though compact fluorescents were MUCH more expensive then, I would buy one whenever I needed to replace a bulb. They let off less heat, and last a long time. I took them with me when I moved, packed an egg carton. They were worth every penny.

Linda Wilson of AZ 10:40PM April 01, 2010

Those are great tips, short of installing a geothermal system. Here is a great example http://geothermalexperts.net/residential_systems.html

Sandy of FL 6:40PM August 20, 2009

A basic principle: it takes far more than two times the energy to cool the air two degrees than to cool it one degree. As with wind resistance & speed, it's a geometrical relation, not an arithmetical one.

Cool one room more than the rest of the house, & hang out in that room. Put your TV, computer, and exercise machine in that room. With kids, you'll need 2 rooms.

When showering, use cool water for a few minutes before you get out. This feels good & lowers your body temp so you won't get all sweaty as soon as you get out. The cool water takes a few minutes to draw the heat out of your body. (You'll find out how long it takes by the amount of after-shower sweating.) Drying/dressing in front of a fan while damp enhances evaporative cooling. Do one or both & you won't need as cool a room to get dressed in.

Set the AC to “not-hot”, instead of cool, 77 instead of 72. (Losing weight? Eat until “not-hungry” instead of full.)

Reduce your sunny-day cooling load with a sprinkler hose along your roof ridge. Attach it to the roof cap with some bent wire, & run a lightweight hose to the ground. Running it on hot days for just long enough to wet the roof will cool the roof & all the structural materials under it. The water will evaporate quickly at first; it can take about 5-8 minutes (a shower's worth of water) to cool it to the point where it leaves the whole roof wet. On a very humid, 100-degree day, doing this once mid-afternoon & once about 3 hours before sunset reduces the inside temperature about 10-15 degrees for the evening in a wood-framed ranch house with 14" of attic insulation. With no AC. Those rafters/trusses & shingles can hold a lot of heat & radiate it down into the house thru the night. This works on humid days, too, because the roof temperature is so much hotter than the air temperature that it reduces the relative humidity at the roof surface. It's the evaporation that does the cooling, so when the roof is fully wet, shut off the water.

AC was rare before the 60s, and people lived without it. The "never let 'em see you sweat" aesthetic is a result of anti-perspirant advertisers' playing on people's social insecurities & subconsciously manipulating them to perceive sweat as disgusting. This manipulation has been effective, & this aesthetic has made AC a kind of sacred cow. One hears often about the energy waste of SUVs and incandescent bulbs, but rarely about the aggregate energy cost of AC, which is far bigger than both of the others. Keep your body clean, and sweat isn't a problem. Question those manipulated intuitions and associations and generate some indignation about having been manipulated by Madison Ave. You can still keep cool, but you'll do so by choice, not because of some neurotic compulsion you've been conditioned into by big business to sell anti-perspirants.

Bob of MA 2:49PM August 25, 2008

My father owns an HVAC company, so I grew up with this stuff. DO NOT turn off your A/C. On a hot day, your house can get up to 80+ degrees. Then your A/C has to work twice as hard to get the house back down to a comfortable temperature. Instead, learn to live with a few degrees colder/warmer (depending on the season) than usual. Your body probably wont notice much chanage. Instead of 70, keep your house at 72 in the summer. When going to work, you can bump it up to 75. If you have a programmable thermostat, this works great. However, don't sway any more than a few degrees from what you would normally set it at. This will cause moisture in your house to build up, damaging food, furniture, etc. and not very effecient for your A/C, causing it to work very hard and reducing the life.

Also, especially important if you have a 2 story b/c heat rises - keep your fan on at all times, not on auto or put fans upstairs. This will cool the upstairs and allow you to keep the stat set a little higher than usual.

of OH 11:14AM August 25, 2008